Electric welding machine



BEST AVMLABLE COP` Jan.Y 6. 1925.

Qs. TILDEN ELECTRIC WELDING MACHINE Filed Jan. 5, ,1921 `4 Sheets-Shoe?t 2 BEST AVNLABLE Com Jan,- 6. 1925'.

- c. s. r|rLDEN ELECTRICWELDING MACHINE v 'Filed Jan, s, A1921 A 4 sheets-sheet s Jan, 6. l'

C. S. TILDE N f ELECTRIC WELDING MACHINE Filed Jan. 1921 4 sheets-super 4 BEST AVAfLABLE com Patented Jan. 6, 1925.

.PATENT OFFICE.

CHARLES AS.l TILDEN, OF CLEVELAND, OHIO.

ELECTRIC WELDING MACHINE.

Application led January 3. 1921.

To all wlw/'lzy t may concern.'

Be it known that I, CHARLES S. TrLDnN, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Electric Welding Machines, of which the following is a specification.

In the electric butt-welding of tubing, and particularly of steel-tubing, it is known practice to pass open-seamed tube-stock through a. welding throat that is formed by seam-straddling roller electrodes and tubesupporting roller-means, complementally grooved; the size of the throat or pass being such as to squeeze the seam-edges together under requisite pressure, and the current that is supplied to the copper electrodes being of suitable voltage and amperage to heat the tube-stock for effecting the weld.

Although machines as above characterized are commercially operated with success, I have found a grave difficulty to existin the maintenance of proper welding conditions because of the action of the tube-stock upon the roller electrodes under those conditions requisite forpwelding, namely,"the heating of the stock to welding temperature at its edges, and the application vof verf-considerable pressure upon the stock in its passage past the seam-straddling electrodes. Under such heat and such pressure the lnetal along the seam is always more or lessiextruded into the space between the confronting electrodefaces; particles of it fuse withparticles ot' the copper, especially at and near the electrode-edges where the side faces and the contact-grooves meet; flecks, chips and slivers of steel and oxidized metal attach themselves to the contact surfaces or grooves and to the faces of the electrodes; and in a run of the machine these conditions develop cumulatively, inevitably and rapidly decreasing the effectiveness of the machine and sometimes causing its complete failure to weld the stock. N ot only does the tendency of the electrodes to accumulate these steel or steel-and-copper particles or growths between their confronting faces tend toward, and sometimes result in, short-circuiting of the electrodes, but the adhesion of such particles, chips and growths to the arcuate coutact surfaces of the electrodes causes the electrodes to be forced out of proper contact with the tube stock in spots, thus vary- Seral No. 434,663.

ying the resistance of the welding circuit,

and current. supply conditions, above referred to, all react on the'tube stock in its passage through the welding throat and militate against successful welding, espe,- cially ina high-speed machine; i. e., one through which the tube-stock is fed rapidly.

I have discovered that the electrodes may successfully and effectively be maintained in good operatingvcondition, substantially free from roughness, pitting and particle` accumulation, in thercontinuous operation of the machine, and with consequent betterment of the product, by combining with each' electrode a suitably constructed profiling tool, constantly' working thereon, for removal of adhering particles from, and for constantly tending to true the surfaces of, the electrodes; and in such combination and further the construction and arrangement of a suit-able tool features of my present invention reside.

In the drawings, Fig. 1 is a side elevation with parts broken away showing portions of a tube-welding machine enibodying my invention; Fig. 2 is a vertical section on line 2-2 of Fig. 4; Fig. 3 is a front elevation of the tool vand holder; Fig. 4 is aplan View of parts shown in Fig.r1; Figs. 5 and (i are plan and side views of a tool; Figs. 7, 8 and 9 are details of a tool of slightly modified form; and Figs. 10, 11, 12, 13, 14 and l5 are details of another modified tool.

In Ithe drawings I haveshown as a single machine, equipped for embodying my invention, a general construction adapted for high-speed tube-welding but it will be understood that changes may be wrought in the machine construction and accordal'itly in The specific form of the tool associated therewith, within the spirit of my invention.

lhe \\'eldingmachine proper is illustrated as comprising a tube-stock-forming section BEST AVAILABLE com l of suitable construction to form strip steel into open-butt-seamed stock, 11 indicating a longitudinal frame-piece or Stringer, and 12 a frame-standard thereof, while 13 indicates a air of positively-driven rolls conventional y representing the last tubeforming pass. If such a tube-forming section is used, it may deliver the stock directly to the welding .i etion 14, the roller elements of which ma be frictionally rotated by the passing stock. Thus in frame extension 15 the companion roller electrodes 16 and 16 are rotatably mounted, these being electrically connected by suitable means with the terminals of the secondary circuit of a transformer 17 adapted to supply al- -ternating current of suitable Voltage and amperage thereto. While such electrodes, circumferentially provided -with contact grooves 18 of arcuate section may be separately mounted and wholly disconnected one from the other, I preferr to employ a. construction as shown, wherein the two electrodes have their confronting faces in perfeet parallelism, electrically separated but mechanically coupled together, as by suitable provision of insulated bolts 19 and an insulating separator structure 20, the insulation 2O being set back somewhat from the grooved portion of the electrodes 'so that at he center of the arc spanned electrode .grooves there is a narrow, parallel Walled circumferential slot recess 21 in register with the center of which the seamcleft of the tube stock will travel in the operation of the machine. Suitable roller means,-for example, the grooved guiding and sup orting roller 22 horizontally disposed be ow the electrodes may be provided in .any desired form and arrangement to complete the welding throat, the circular pass or opening afforded by these coacting roller members being of slightly less diameter than the diameter of the tube stock. The

machine, as thus far described, typifies one now-known construction, for illustrative purposes, and its operation is understood by those skilled in the art.

In combination with the roller electrodes I provide a tool comprising generally a pair of electrically separated or insulated f profiling members having their active or'dutting ends shaped in conformity with the crosssectional contours of the two respective electrodes throughout their contact grooves 18 and preferably conforming also to the confronting border portions of slot 21 immediately adjacent said grooves, these two insulated tool members being: so disposed as constantly to coact smoothly with the said 'surfaces of the-electrode rollers, constantly to clean the latter and preserve the smoothness and true shape of the affected surfaces. Specifically, since the electrode rollers are preferably mechanically united, as stated, so

.hand members-23, 23', each being a rectangular toolssteel bar with its forward or active end having a cutting edge 24 shaped, in plan, to correspond with a section of the grooved periphery of the respective roller electrode, and with a small slot-clearing projection 2G arranged to enter the slot between the electrodes. This front end ofthe tool is sloped back from the cutting edge as shown to provide draft or clearance in a fashion common in cutting tools. Between thev two tool men'ibers isdisposed a mica strip 27 th'at (integrally or by an added piece) projects above the cutting edge 24 and beyond the end of the tool, -so forming a fin 27 of insulating material to prevent bridging of metal-pieces across the insulating strip of the Ltool. These two tool sections may be secured'togetherby suitably inl ',sulated bolts 29. In some welding work it jointly by'the/ is desirable that the contact Agroove 18 and slot-face of the electrodes shall not meet .in a sharp line, and when this isa desideratu'm the-tool (as shownin Fig. 5) maybe provided with a slight fillet 30 to lcorrespond with the desired Au'rve of the electrode edge.

vloo I In Figs. 9 and 10 I have shown slightly modified forms of the tool,`Fig.'- 9 illustratinga construction with a raised nose or plow formation 25 at its cutting edge for the groove-conforming portionfof the tool, and" with the Yslot-clearing projections 26 provided on thin plates 31 that are mounted fiat against the confronting surfacesl of the tool 'members for ready replacement when worn 1 or broken. In Figs. 10 to 15 the tool is made with a spring shank having its'springbow or yoke at 32 to make the active end somewhat yielding and to prevent chattering of the tool. In this instance the removable plates 31 and 31 are made to extend only tothe spring yokewhile, in order to prevent slivers of steel fronr puncturing the mica fin 27 the greater portion offs'uch fin is metal-reinforced, being shown as 'overlain on each side by a very thin covering plate 33 of steel.

l'When used in a machine as hereinbefore specifically described, either stated form of tool will be mounted so that its cutting edge coacts with the electrodes substantially on a horizontal diameter thereof, preferably on the side from which the tube-stock is fed to the electrodes, and while the mount-ing maybe variously contrived I preferably sEsT AVAiLABLE coin employ a mounting as follows: On the frame members 1l, 12 is bolted, at end and top, a base block 35, the retaining bolts vby an underlying wedge 4Q fastened by a screw 42 which takes through a down-turned front lip of the wedge and is threaded into the base. block 35. To the, lower rear poi'- tion of the base block is connected a detach- .able bracket 44 slotted to enga-ge between collars on a feedscrew 45 which at one end carries a handwheel 'H and atits other end is threaded into the tool slide 3f). The tool 23, 23 is enclosed around its four sidesfbj; au envelope .4T of insulating material and :s placed in the aperture 4.1 of its slide torest on a shim or shiuis 48 (if necessary). where itis secured bya clanip plate t9 laid over the top of the tool bar and boriieupon by .set-screws 5() tightly to hold the, tool in place. Manifestly with the fore-and-af t. adj ustnient of the tool slide by the handwheel and feed screw, the vertical adjustability of the toni in its carryingr slide b v addition or removal .of shiins and the transverse adjustment of the base block on the machine frame, perfect positioning of the. tool for its worl: may be attained.r

Preferably, further, to prevent seiapi-ngs from the electrodes from falling on the stock and being carried through the welding throat I secure a shield-plate 52 to the bot tom ot' the base-block 35, extending said plate 1laterally beyond the tube-stock and forward beyond the end of the tool.

I have found that by constantly 'scraping and truing tbe electrodes I am enabled greatly to aid in securing rapid, continuous` and perfect welding, and that by -the use of my invention not only is electrode life prolonged and maintenance expense' reduced but many difficulties in the commercial electricbutt-welding of tubing are overcome that heretofore have been normally encountered and heretofore have erroneously been regarded as flowing from faulty current-regulation or from defective tube stock or improper surface conditions in the tube st'ock: such diiiculties have heretofore been sought to be remedied by expensive and ineffective expedients along other lines, but I believe that I am the first person to prevent their occurrence. It will be understood by those skilled in the art` that in its broader aspects in v invention is susceptible ot many changes in detail and in carrying the saine out in connection with machines of specifically different electrode-arrangement from that herein illustrated and under 'other variant conditions of application. within the scope of the appended claims. 'L

I claim: f t

1. In a machine for electrically buttwelding tubing, the combination with bipolar coaxial relatively-insulated roller electrodes and means coacting therewith to form a-'lwelding throat. of elmitrode-cleaning means comprising an insulated two-part tool, each of said parts arranged to act upon the entire. contact surfaces of said electrodes to remove adhering bodies therefrom;

2. In a machine. for butt-welding tubing` means forming a welding throat iiufliidiir;r a pair of grooved electrodes relatively-in sulated and compleniental grooi'ed roller means, in combination with a pair of cleaning-tool members relatively-insulated 'from each other'respectively shaped for profilingr the electrode contact surfaces, and means for securing said tool members iu position to act onI said electrodes.

3. In a machine for electrically butt-welding tubing, the combination -with a pair of peripl'ierally grooved opposing roller-electrodes having a space between' their coufi'onting faces and complementally-grooved roller-iiieans forming'with said electrodegrooves a tube-stock-constricting throat` of a pair of profilingtool members insulated from each other and disposed respectively to act 4upon the confrontjng edge-portions and contact-groove surfaces ofthe electrodes.

4. In a machine for electrically butt-welding tubing, the combination with peripherally grooved opposing rollerelectrodes and complemental roller-means forming with said electrode-grooves a tube4stock constricting throat, of a pair of profiling-tool` members insulated from each other and disposed to act upon the contact grooves of the electrodes, and means rigidl)r connecting said" tool members together.,

5. A. metal-cutting tool for profiling opposed energized electrodes comprising' complemental profiling sections insulated from each other. d

6. A metal-cutting tool for profiling opposed energized elect'rodes comprising complemental profiling sections insulated from each other, and secured together to forni a unitary structure.

7. A metal-cutting tool for profiling opposed complemental energized electrodes comprising complemental profiling sections, an interposed insulating body extending in a fin beyond the cutting portions ofsaid sections, an insulated means, uniting said sections and the insulating body.

8. A metal-cutting tool for profiling op` posed complement-al energized electrodes comprising coniplemental profiling sections, an interposed insulating body extending in- BEST AvAiLAeLE com 1 Welding tubing, the combination of a frame,

opposed roller electrodes and complemental rolls thereon forming a welding throat or pass, a pair of profiling tool members for removing metal bodies from the Contact sur- ,faces of the respective electrodes and means for feeding said tool members simultaneously toward the electrodes.

11. In a machinev for electrically-butt welding tubing, the combination of a frame, opposed Vroller electrodes und complemental roller means thereon, forming` a welding throat or pass, a profiling tool for removing metal bodies from the Contact surfaces of the electrodes comprising tool sections insulated from each other, a holder for said tool sections, a base for said holder mounted on the machine frame, and means for adjusting said holder with respect to said base.

l2. In a machine for electrically butt- Weldin tubing, the combination of a frame, opposed roller electrodes and complementari roller means thereon, forming a welding throat or pass, a profiling tool for removing metal bodies from the contact surfaces of the electrodes comprising tool sections insulated from each other, a holder for said .tool sections, a base for said holder mounted on the machine frame, means for adjusting said holder with respect to said base, and means for adjusting said base with respect to the machine frame.

13. In a tube Welding apparatus, a welding roll comprising two welding members for engaging the tubing on opposite-sides of the seam, said roll being provided with a groove for receiving the tubing, a transformer having a secondary including pole pieces disposedl adjacent to the respective welding members and electrically connected thereto, means yfor dressing the roll comprising a two-part tool in 'constant contact with said roll, said parts separated by a project ing insulating n, and arranged to simultaneously dress the periphery of the welding members.

CHARLES S. TILDEN 

